Olive Leaf Extract Improves the Atherogenic Lipid Profile in Rats Fed a High Cholesterol Diet

Abstract

Coronary heart disease because of atherosclerosis is still the most common cause of mortality. Elevated levels of low-density lipoprotein and total cholesterol are major risk factors for atherosclerotic cardiovascular disease. The aim of this study was to evaluate the effects of the olive leaf extract on serum lipid profile, early changes of atherosclerosis and endothelium-dependent relaxations in cholesterol-fed rats. For this purpose, rats were fed by 2% cholesterol-enriched or standard chow for 8 weeks. Some rats in each group were also fed orally by olive leaf extract at doses of 50 or 100 mg/kg/day. Atorvastatin at dose of 20 mg/kg of body weight daily was also given as positive control. After 8 weeks, lipid profiles of rat serums were analyzed. Antioxidant enzyme activities (superoxide dismutase and glutathione peroxidase) and degree of lipid peroxidation (malondialdehyde levels) were also measured in the hearts isolated from rats. In addition, expression of adhesion molecules and endothelium-dependent relaxations of isolated thoracic aortas of rats were evaluated. Total cholesterol and LDL-cholesterol levels were found to be increased in cholesterol-fed rats, and both doses of olive leaf extract and atorvastatin significantly decreased those levels. In conclusion, because the olive leaf extract attenuates the increased cholesterol levels, it may have beneficial effects on atherosclerosis.

Dietary solutions to dyslipidemia: Milk protein–polysaccharide conjugates as liver biochemical enhancers

“…The serum obtained was used to estimate the triacylglycerides (TAGs), total cholesterol (TC), and high‐density lipoprotein (HDL), which were determined by enzymatic methods with an automatic analyzer (Diamond Biodiagnostic ©, Hannover, Germany). Low and very low‐density lipoprotein (LDL, vLDL) and atherogenic index of plasma (AIP) were calculated according to Olmez et al (). Also, the enzymatic parameters (Alanine aminotransferase—ALT; aspartate aminotransferase—AST; aspartate transaminase—ALP), albumin and bilirubin were measured using commercial assay kits (Randox laboratories ©, San Francisco CA, USA) according to the manufacturer's instructions.…”

“…were calculated according to Olmez et al (2015). Also, the enzymatic parameters (Alanine aminotransferase-ALT; aspartate aminotransferase-AST; aspartate transaminase-ALP), albumin and bilirubin were measured using commercial assay kits (Randox laboratories ©, San Francisco CA, USA) according to the manufacturer's instructions.…”

Citrus junos Tanaka peel ameliorates hepatic lipid accumulation in HepG2 cells and in mice fed a high-cholesterol diet

“…Several recent studies demonstrated that consumption of plant extracts decreases the level of LDL, an important factor for cardiovascular diseases. Increased level of cholesterol results in atherosclerosis due to the increased lipid peroxidation [14–16]. Thus, LDL peroxidation is an important target for the prevention of atherosclerosis and can be prevented by antioxidants.…”

Potential Health Benefits of Olive Leaf

“…Sonuç olarak zeytin yaprağı ekstresinin aterosklerozda olumlu etkilerinin olabileceği belirtilmiştir. 33 Zeytin yaprağının östrojen eksikliğinden kaynaklanan dislipidemi tablosunu iyileştirdiği hipotezi ile overektomili ratlar üzerinde yapılan bir çalışmada, 10 hafta boyunca 200-400 mg/kg zeytin yaprağı ekstresi verilen ratlarda alım süresi sonunda kontrol grubu ile karşılaştırıldığında serum trigliserid ve VLDL seviyelerinde anlamlı bir azalma olduğu gözlenmiş ancak LDL düzeyinin değişmediği belirtilmiştir. Ayrıca yüksek dozda zeytin yaprağı ekstresi alımının serum östradiol seviyesini anlamlı ölçüde arttırdığı belirtilmiştir.…”